After some more attempts, we got a clean log file of at least one of the three error messages on PC (“Network Connection Lost”). Here’s a video and full game log of this error:
https://www.youtube.com/watch?v=ywsTJM5Oj2Q
FortniteGame-ErrorJoining.log (4.0 MB)
Comparing this log to a working game join log yields this specific error:
LogNet: NMT_CloseReason: (Server Disconnect Reasons) 20.185.51.181:9045
LogNet: - HostClosedConnection
LogNet: UNetConnection::SendCloseReason:
LogNet: - Result=FailureReceived, ErrorContext="FailureReceived"
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = FailureReceived, ErrorString = DataStreamChannel failed to write data., Driver = Name:GameNetDriver Def:GameNetDriver IpNetDriver_2147482636
LogNet: Warning: Network Failure: GameNetDriver[FailureReceived]: DataStreamChannel failed to write data.
LogNet: NetworkFailure: FailureReceived, Error: 'DataStreamChannel failed to write data.'
LogFort: [HandleDisconnectInternal] bHandlingDisconnect: false
LogParty: Verbose: UFortPartyMember::HandleLocationChanged for [Jacobg1998] from [InGame] to [ReturningToFrontEnd] in [None]
LogFort: [3af2] New Session Started - PlayerLeftVoiceGameChannel flag was reset
LogParty: Verbose: UpdateChangeCallbacks: Getting Team Member Info for [Jacobg1998] Id [MCP:de0dff7dd1184545a25d97a8c8227c9a].
LogParty: Verbose: [Jacobg1998] Id [MCP:de0dff7dd1184545a25d97a8c8227c9a] team member data updated, team [MAX] at index [0] in [Jacobg1998]'s game.
LogMatchmakingUtility: [HandlePartyMemberLocationChanged called] MCP:de0dff7dd1184545a25d97a8c8227c9a, Party (V2:5d90aa0611d749cea7f34ad4ac8cafb7) location changed to: ReturningToFrontEnd None
LogNet: UNetConnection::Close: [UNetConnection] RemoteAddr: 20.185.51.181:9045, Name: IpConnection_2147482636, Driver: Name:GameNetDriver Def:GameNetDriver IpNetDriver_2147482636, IsServer: NO, PC: Athena_PlayerController_C_2147482642, Owner: Athena_PlayerController_C_2147482642, UniqueId: MCP:de0dff7dd1184545a25d97a8c8227c9a, Channels: 3, Time: 2025.07.17-18.05.59, TimeSinceTickDispatch: 0.035244, TimeSinceRecv: 0.001937, TimeSinceTickFlush: 0.622237, TimeSinceSend: 0.622186
LogNet: UNetConnection::SendCloseReason:
LogNet: - Result=FailureReceived, ErrorContext="FailureReceived"
LogNet: UChannel::Close: Sending CloseBunch. ChIndex == 0. Name: [UChannel] ChIndex: 0, Closing: 0 [UNetConnection] RemoteAddr: 20.185.51.181:9045, Name: IpConnection_2147482636, Driver: Name:GameNetDriver Def:GameNetDriver IpNetDriver_2147482636, IsServer: NO, PC: Athena_PlayerController_C_2147482642, Owner: Athena_PlayerController_C_2147482642, UniqueId: MCP:de0dff7dd1184545a25d97a8c8227c9a
LogNet: Error: UEngine::BroadcastNetworkFailure: FailureType = ConnectionLost, ErrorString = Your connection to the host has been lost., Driver = Name:GameNetDriver Def:GameNetDriver IpNetDriver_2147482636